The invention is in the field of conveying technology and relates to a conveying system for conveying material along a conveying line. Such a conveying system comprising guide means extending along the conveying line and at least one conveying element that is movable along the conveying line and guided by the guide means and driven by a suitable drive. The guide means and conveying element are designed for conveyance of items substantially independent of gravity. At least one conveying element being movable along the conveying line with or without the material while being guided by the guide means and being driven by a suitable drive. The conveying line can be designed such that conveying element and material to be conveyed can have different spatial positions in different locations of the conveying line.
Conveying systems with a guide means and with at least one conveying element movable along the guide means for which conveying system the spatial position of the conveying element and the material to be conveyed can be different in different locations of the conveying line are, for example, known as comprising a conveying chain running in a guide channel and carrying grippers protruding from the channel, wherein each gripper grips an item (material to be conveyed) and supports it during conveyance. This kind of system is, in particular, known from its application in conveyance of streams of printed products in substantially all possible spatial positions.
Similar systems are known that use, instead of a transport chain with a plurality of links, a plurality of conveying elements that are independent of each other and driven individually. Further known are systems combining characteristics of both systems mentioned above by using a plurality of conveying elements being connected to each other but with distances between each other which are, to a limited degree, variable.
For conveyance to be substantially independent of gravity the guide means of the named conveying systems are, for example, designed to form a cage or channel in which a guided part of the conveying element is enclosed (guided part within guiding part) or to be surrounded by a part of the conveying element (guiding part within guided part). The conveying elements are grippers that are designed for gripping and supporting items to be conveyed.
Conveying systems for conveyance in particular of printed products along freely selectable conveying lines and substantially independently of gravity, are described in the following publications CH-623283 (F086) CH-592562 (F070), EP387318 (F270).
The guide means of conveying systems as described above are usually mounted along a conveying line being predetermined by the conveying function. For simple mounting of the guide means along curved regions of conveying lines bendable guide means have been described, e.g. in the patent applications CH-2917/96 (F444) and CH-801/97 (F453) or in publication EP-0628109 (Richter).
Usually switch points are used for connecting the end of a conveying line defined by a fixedly mounted guide means to a selected one of a plurality of further conveying lines or to a selected one of a plurality of different installations. Such switch points, for example, consist of a pivoting guide piece having a restricted length and being hingedly connected to the end of the fixedly mounted guide means. This pivoting guide piece can be pivoted such that its distal end facing away from the fixedly mounted guide means connects the fixedly mounted guide means to one or another of the further conveying lines or installations.
Such switch points restrict the arrangement and design of possible connecting points to be connected with the fixedly mounted guide means within narrow limits. The connecting points must have an exactly defined distance from the end of the fixedly mounted guide means. The connecting points must all lie in the pivoting plane of the pivoting guide piece and they must all be designed such that they can take over conveying elements and/or conveyed items with the same orientation defined by guide means of the conveying line further upstream and the switch point. The same is valid for switch points according to CH-558285 (F61) which comprise a bendable guide piece instead of a pivoting guide piece.
Selectable connection of a conveying system, as described above, to one of two connecting points is, in most, cases realized by a fixedly mounted guide ramification and a controllable switching element (e.g. flap in a canal ramification) with two positions. The switching element in each one of the two positions forces movement of a passing conveying element to one of the two guide means branching away from the ramification point.
An object of the invention is to create a conveying system with a guide means extending along a conveying line and with at least one conveying element, which conveying system is selectively connectable to one of a plurality of connecting points. The inventive conveying system is to restrict to a considerably lesser degree than known conveying systems the conditions regarding spatial position of the connecting points and spatial position of the conveyed items. The term xe2x80x9cconnecting pointxe2x80x9d is to be understood as an area in which either the at least one conveying element (e.g. together with conveyed items) passes from the guide means of the regarded conveying system to a further guide means (connection to a further, similar conveying system) or in which the conveyed items are transferred from the at least one conveying element of the regarded conveying system (connection to a further different or similar conveying system or to a different installation with transfer of conveyed items).
The inventive conveying system comprises, following an invariable region of conveying line with a fixedly mounted guide means, a variable conveying line region. The variable conveying line region comprises a guide piece, which is reversibly bendable and twistable such that the end of the guide piece, by predetermined bending and/or twisting, is selectively connectable to one of a plurality of connecting points. The variable conveying line region is e.g. the end region of a conveying line. The bendable and twistable guide piece is bent and/or twisted in a predetermined manner and held in the bent and/or twisted position with the aid of a drivable connecting means which e.g. acts on the distal end of the bendable and twistable guide piece.
In further accordance with the present invention, the variable region of conveying line does not have to be an end region of a conveying line. An intermediate region of a conveying line can also comprise a bendable and twistable guide piece and thus act as a connecting region. The bending and twisting capacity of the guide means in the variable conveying line region is to be matched to the at least one conveying element such that conveying line curves created by bending and/or twisting have a bending radius which is at least large enough for the curves to be passed by the conveying element without problems.
The length of the reversibly bendable and twistable guide piece in the variable conveying line region is advantageously matched to the mechanical stability of the guide means such that the form of the guide piece is defined by its connection with the at least one fixed guide means and the effect of the connecting means and such that it has (advantageously without further devices) a stability sufficient for operation, i.e. is self-supporting.
If the guide means in a conveying line end region is bendable, the end of the conveying line can be coupled to connecting points at different distances from a fixedly mounted region, arranged in space in any manner. Thus, for different connections, the guide means is bent more or less, in different directions or forming a loop or loops. If the guide means in a conveying line end region is twistable, the spatial position of the conveying element and thus of the conveyed items can be matched to specific requirements of each individual connecting point.